Well it might be good for grass but I think it not a good argument when a food staple of billions of people depend on rice which gets less nutritious the higher the CO2. And that is just one effect, the other being heat retention.
And I know there are other GH gasses like Methane and water. Methane at least is more temporary even though it is some 25X more efficient as a GH gas, it gets destroyed by ozone and UV, but it takes about 30 years to complete that cycle.
If for instance all the permafrost melted, a huge influx of methane would shoot into the atmosphere and really raise even further hell with our climate but it would be done in one generation as opposed to CO2 which without powerful technological solutions, will be around for centuries.
If it got bad enough we would have to settle down on the moon, Mars and maybe outer moons of Saturn and Jupiter. Venus is out of the question, 1500 PSI atmosphere of sulfuric acid and temperature of 900 degrees F.
The Russians sent a probe to the surface of Venus a few decades ago and it was a slick spacecraft, it had liquid nitrogen cooling lines wrapped around the probe so it could last long enough for some science. Even with that, it lasted all of 20 minutes but they did get some surface photos back to Earth.
There isn't ANY kind of electronics that can run at 900 degrees at least in THIS century.
The outer moons would be the other way round, no atmosphere except Titan which has an atmosphere about the same as Earth, ~15PSI but mainly methane and there are massive liquid methane lakes there and weather too but a couple hundred degrees below zero which is the only way you would have liquid methane.
Most of the big Jovian and Saturn moons have buried liquid oceans of water which may be the best place in the solar system to search for alien life.
For instance, Europa has jets of water shooting out of the surface hundreds of miles high and that leaves the possibility of shooting a probe, which is in the works at NASA, to fly through those jets and collect the water with paddles and such.
Bring it back to Earth and do a search for microbes and such and my question if so would be, assuming we do find some kind of life there, even just microbes, does it have the same DNA base as Earthy life or is it some other kind of structure we know nothing about, say instead of a corkscrew ladder, maybe a corkscrew structure like a triangular radio tower or a box square structure, just totally hypothesis but that would be what they would look for if there is in fact any life to be found there.
And of course Mars, they are near 100% certain there will be SOMETHING there, maybe just fossil microbes but if we get there with enough scientists I am sure they will find it somewhere. There was massive amounts of water for hundreds of millions of years there and my assumption is any place there is water, minerals and energy like early Mars had, life will find a way. I expect they will find life on the moons of Jupiter and Saturn and now they have figured out even Pluto has buried liquid oceans, most likely water so it doesn't matter much how far you happen to be away from the sun to have liquid water since several geological processes can cause enough heat internally to allow liquid oceans buried under the surface and so will not evaporate like the water that used to exist on Mars in significant quantities.
Even OUR moon has water, ice, but water, in craters that never get sunlight so never has the energy to melt ice and therefore immediately evaporate.
Thing about that is, if we establish colonies on the moon, near the south pole, you get water to drink and such but electrolytically separate the H and O so you get oxygen to breath and hydrogen as fuel, for rockets and electric fuel cell vehicles.
Of course this is all in the future, maybe 50 years from now before any of that bears fruit but it will be done barring a world wide catastrophe.